Telephone signaling apparatus



(No Mddel.) I

' J. J. GARTY.

TELEPHONE SIGNALING APPARATUS.

No. 288,691. Patented Nov. 20, 1883.

'UN'iTED STATES PATENT OFFICE.

JOHN J. oAnrY, or CAMBRIDGE, ASSIGNOR TO THE AMERICAN BELLTELE- PHONECOMPANY, OF BOSTON, MASSACHUSETTS.

TELEPHONE SIGNALING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 288,691, dated November20, 1883.

Application filed October 4, 1883. (No model.)

I To aZZ whom it may. concern Be itknown that I, JOHN J. CARTY, of Cam-.bridge, in the county of Middlesex and State of Massachusetts, haveinvented certain Improvements in Telephone Signaling Apparatus, of whichthe following is a specification.

My invention relates to electric-signal bells, such as are used inconnection with telephones for signaling between stations. It hasparticular reference to an improved combination of the cut-out orshort-circuiter with the working parts of the said bells.

In the ordinarymagneto-telephone bell it is usual to combine athrough-circuit for the signal-bell magnet, a branch circuit of the samethrough the generating-helix, this latter being normally shunted by ashort wire, the said shunt being adapted to be broken when the generatoris operated either by a manual circuit-breaker or by an automatic deviceattached to the generator-crank. A second circuit, whereby the line isdirected through the telephones, is also incorporated in the bellmechanism and adapted to be included in the main line when the telephoneis removed from its support. It has been common in telephonestationapparatus of the foregoing character which approximate to one another,so that a metal plug may be inserted in the hole thus formed to unitethem electrically. WVhen a plug is soinserted it forms practically acutout or short-circuit round the entire bell. Persons having the chargeof the telephone are instructed to insert the plug on the approach of alightning storm, so that the bell coils may be protected from injury. Inthe use of this device it has been found, in practice, that after theplug has been inserted to to use the telephone, through forgetfulness ornegligence, omits to withdraw the same upon discontinuance of the storm,and thus the'bell is rendered useless, and cannot be utilized until thefact that the cut-out plug is inserted is discovered, and the plugwithdrawn. The telephone connected with the apparatus is from the samereason inoperative.

The object of this invention is to prevent this omission; and to thisend the invention ning-arrester in such relation to the operatingcrankof the generator that if the said plug is in position to short-circuitthe bell, it also forms a mechanical obstacle to the revolution of thecrank, -so that the crank cannot be turned until it be withdrawn.

Heretofore it has been the uniform practice to place thelightning-arrester and its concomitants on the top of the bell, aposition in most cases above the range of vision of the operator,

the operator. In this invention I place it on the side or front of thebell, within the radius of the operating-crank. so that its positionwill at once be-noted by an intending operator; or, in the event it isnot noticed, it will by the concussion of the crank with theshortcircuiting plug before the completion of the first revolution.

The accompanying drawings illustrate, the manner in which the principleof my invention is carried into effect.

Figure 1 is a side elevation of a magneto short-circuit the bell, theperson accustomed either for sending or receiving call-signals,

be brought to the attention of said operatorconsists in placing thecut-out plug and lightand not at all adapted to attract the notice ofcallbell with the cut-out plug inserted and the crank in its normalposition. Fig. 2 is a diagrammatic View of the several circuits; andFig. 3 is a detail showing the position of the crank when, an attempt ismade to operate the generator while the cut-out plug remains in serted.

In Fig. 1, A is the bell-box, B the crank by which thegenerating-armature is rotated, and all the short'circuiting pluginserted between fthe lighting-arrester plates at and a, which areplaced .011 the side of the box in immediate proximity to theground-plate I). I will now describe the diagram in Fig. 2, by which theI efficiency of my device will be made apparent.

The main-line wire I, entering the instrument, is attached to thecut-out plate a, from thence it passes by wire 3 to the call-bell magnetD, and thence by wire 4 to the switch-hook WVhen the telephone is inplace on the hook, the circuit is continued through the spring 6, wire6, springsi and j, and wire 8 to the oppbsite lightning-arrestcr platea, to which is attached the outgoing line 2. A branch-circuit is ledfrom the wire 6 to the wire 8, by means of the spring 9, generating- I 5armature E, spring h, and wire 7 but this circuit, with the generator E,is normally shortcircuited by the springs z and j with the connectingwires, but may be made a part of the main circuit by pressing the buttonK, and

thus separating the springs and j. When the telephone is taken from thehook, the said hook flies up and makes contact with the spring (I, atthe same time breaking the original contact with the spring 0. Thecircuit then con- 2 5 tinues from the wire 4 to the spring (1, wire 5,telephone T, and transmitter T, wire 9, and plate a to the out-wire 2.The ground-plate I) is, as shown, connected with the ground G. Betweenthe ligntning-arrester plates a and a 30 is a hole, 0, wherein a cut-outplug, 0, may be placed. WVhen a plug is so placed, the entirearrangement of circuits and electro-magnets within the bell-box isshort-circuited, the line-circuit passing from the line-wire I to 3 5plate a; thence by plug 0 to plate a, and to the outgoing line 2. Inpractice, these plates are placed upon the side of the box, as in Fig.

1; and the only object in showing the circuit arrangement, as in Fig. 2,is that the function of the said plates and their plug may be ap- 0parent. When thus placed, while the plug is in, it projects outwardlyfrom the side or front of the bell-box, as shown in Fig. 3, in which Ais a part of the boX, a the cut-out plate, I) the ground-plate, and Othe inserted 5 plug. 13 is the operating-crank. The crank is placed, asshown, close to the lightning-arrester, so that if the plug 0 beinserted any attempt to turn the crank will be fruitless, because itwill strike the plug, as shown in Fig. 3. It is self-evident, then, thatin the event of such an impingement, the position of the cut-out plugwill be forcibly brought to the notice of the operator,-who may at onceremove the same.

That I claim as my invention, and desire to secure by Letters Patent ofthe United States, 1s

The combination, with the operatingcrank of a magneto-electriccall-bell, of the light- ,ning-arrester plates and short-circuiting plugJOHN J. CARTY.

IVitn esses:

FRED J. F. SCHWARTZ, G120. WILLIs PIERCE.

